Atrophic Maxilla Rehabilitation with Use of «All-On-Four» Tilted Implants Rehabilitación De Una Maxila Atróﬁ Ca Con El Uso De Implantes Inclinados «All-On-Four»

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Revista Odontológica Mexicana Facultad de Odontología

Vol. 18, No. 4 October-December 2014 pp 249-254 CASE REPORT

Atrophic maxilla rehabilitation with use of «All-on-Four» tilted implants Rehabilitación de una maxila atróﬁ ca con el uso de implantes inclinados «All-on-Four»

Iván Contreras Molina,* Gildardo Contreras Molina,§ Karla Nunes Teixeira,II Pamela Candida Aires Ribas de Andrade,II Marco Aurélio Bianchini¶

ABSTRACT RESUMEN

Maxillary resorption infl icts limitations to implant placement when La reabsorción de la maxila presenta limitaciones en la colocación using conventional techniques. The concept of «All-on-Four» uses de implantes por medio de la técnica convencional. El concepto de distally inclined implants in edentulous arches; it improves denture «All-on-Four» sobre la inclinación distal de implantes en arcadas support and increases inter-implant distance, providing thus greater desdentadas mejora el soporte de la prótesis y aumenta la dis- stability in the bone with the help of longer implants. For over two tancia interimplantar, proporcionando una mayor estabilidad en el decades, different types of therapies have been developed to hueso mediante el uso de implantes más largos. Durante más de rehabilitate atrophic or edentulous arches. Obtained results have dos décadas, diferentes tipos de terapias se han desarrollado en been of a diverse nature. Among proposed techniques we can count la rehabilitación de arcadas atrófi cas o edéntulas, lo cual ha traído bone graft and maxillary sinus elevation. In order to avoid this type resultados diversos. Entre las técnicas propuestas están el injerto of procedures, a different surgical alternative has been developed: óseo y el levantamiento de seno maxilar. Para evitar este tipo de this technique consists on placing four implants, two anterior and procedimientos se desenvolvió una alternativa quirúrgica diferente, two tilted posterior implants, all linked by an infrastructure. The que consiste en la colocación de cuatro implantes, dos anteriores y clinical case here presented describes a technique used to restore dos posteriores, siendo estos últimos inclinados, todos unidos por an atrophic maxilla following the «All-on-Four» concept, with medio de una infraestructura. Este caso clínico describe una técnica immediate load. The patient was subjected to a one year follow- para restaurar una maxila atrófi ca con el concepto «All-on-Four» up and was satisfi ed with the treatment outcome. To this date, no con carga inmediata. La paciente ha tenido un seguimiento clínico clinical or radiographic changes have been observed around the durante un año y está satisfecha con el resultado del tratamiento. dental implants nor have there been prosthetic complications. No se han observado cambios clínicos ni radiográfi cos alrededor de los implantes dentales hasta la fecha, no ha habido complicaciones protésicas.

Key words: Rehabilitation, atrophic maxilla, All-on-Four. Palabras clave: Rehabilitación, maxila atróﬁ ca, All-on-Four.

INTRODUCTION involving lesser amounts of implants as well as their inclination were conducted. Placement of Fixed, implant-supported dentures in edentulous four implants, two in the anterior section and two upper and lower jaws were originally used by placing five to six implants. This was called the Brånemark protocol. In most cases, the maxilla presented moderate to severe resorption,www.medigraphic.org.mx with maxillary sinus * MSc, PhD, Visiting Student at the University of Southern Califor- nia (USC) Dentistry. pneumatization. This system required reconstructive § DDS, Endodontics Professor, University San Nicolas Hidalgo surgery based on bone grafting which could enable (Universidad Michoacana de San Nicolás de Hidalgo), Morelia, the placement of that number of implants. Brånemark Mexico. II protocol prostheses supported cantilever extensions MSc, PhD, Department of Dentistry, Federal University of Santa Catarina, Brazil. which protruded distally due to bone unavailability in ¶ MSc, PhD, Associate Professor, Department of Dentistry, Master posterior regions.1 and PhD in Implantology, Federal University of Santa Catarina, Predictable results were obtained with the Brazil. increase in knowledge of bone integration and This article can be read in its full version in the following page: implant biomechanics. Rehabilitating treatments http://www.medigraphic.com/facultadodontologiaunam Contreras MI et al. Atrophic maxilla rehabilitation 250 tilted implants in the posterior section improved the upper jaw. Several possible treatment options anchorage since they used cortical bone from were discussed with the patient. The concept of the anterior section of the maxillary sinus and «All-on-Four» therapy was proposed, where the the nasal passage (nostril). This represented an patient would receive four implants in the maxilla, alternative therapy to avoid reconstructive surgery and implants would be immediately loaded with a or bone graft procedures. It also represented a less prosthesis. invasive and financially competitive treatment. The Preliminary studies requested were cone beam so-called surgical technique of tilted implants «All- tomography, panoramic and periapical series of both on-Four» and «All-on-Six» consists of a technique upper and lower jaws, study models and extra- and where implants are linked by means of a structure. intra-oral pictures. With all the aforementioned in Tilting of the posterior implants allows the screws hand, treatment planning was undertaken (Figures to emerge in the region of the second premolars, or 1 to 4). first molars, thus decreasing or avoiding cantilever, Impressions were achieved with alginate (Jeltrate, since, when it is minimized, the denture will be Dentsply International, New York) in both dental subjected to lesser mechanical stress.2 The present arches. Study models were obtained, and were clinical report describes a method to restore an mounted on a semi-adjustable articulator, according atrophic maxilla with the «All-on-Four» technique, to classical concepts and techniques. Waxing for using the concept of immediate load. an immediate full denture was undertaken, and it was replicated in order to obtain a multi-functional CLINICAL CASE REPORT surgical guide. All upper teeth were extracted (Figure 5) and a muco-periosteal flap was raised at 59 year old female patient attended the the level of the bone crest, with relaxing incisions in Implantology Clinic at the Dental Implant Study the vestibular section at the level of the molars. A and Research Center (CEPID) at the Federal high speed round diamond burr was used to open University Santa Catarina, Brazil. The patient the maxillary sinus, with external irrigation so as to had been previously treated at the University’s accurately identify the anterior wall of the maxillary periodontics clinic, where several treatments had sinus (Figure 6). been undertaken in order to preserve to the utmost Once the anterior wall of the sinus was located, existing teeth. During her last visit, splinting of all surgical sequence for implant placement was upper and lower teeth had been decided upon, undertaken. The two first implants to be placed keeping them thus functioning in the last five years. were those most distally located, with the following At the follow-up appointment the patient expressed measures: 3.75 x 19 mm, after this, the anterior her wish to achieve better aesthetics; clinical implants were placed, with the following measures examination revealed increase tooth mobility in 3.75 x 15 mm. Implants used were Cone Morse

Figures 1 and 2.

www.medigraphic.org.mxwww.medigraphic.org.mx Initial circumstances of the patient.

Figures 3 and 4.

Periapical and panoramic X-rays. Revista Odontológica Mexicana 2014;18 (4): 249-254 251

(Neodent, Curitiba, Brazil). Instant placement was maxillary-mandibular relationship. Transfers were uneventful. Implants exhibited an upper torque of linked with dental floss, and small increments of 45 N/cm. Multifunctional guide was used at all times Duralay (GC Pattern resin, GO America Inc) resin during surgery to ease implant placement with respect were added in their midst in order to link them. In to the lower jaw as well as proper tilting of posterior this case, inter-implant distance was very large, implants (Figures 7 and 8). therefore, implant molds were used to ease bonding Frontally placed implants are usually placed in and minimize resin contraction. After this, they were the position of central or lateral incisors. Posterior linked to the surgical guide (Figure 9). Once the guide implants can be placed in second premolar or ﬁ rst was in position an inter-occlusal recording was made molar position creating thus a larger inter-implant with Duralay resin. One point in the anterior section distance and a shorter cantilever. Used components and two points in the posterior section were located were conic mini-pillars, the two posterior implants in order to achieve an impression with the patient in were angulated at 17o. All components had a 3.5 occlusion, preserving the same vertical dimension tape. After component installation a 32 N/cm torque (Figure 10). The impression was taken with polyvinyl was applied following manufacturer’s instructions. siloxane material (Express addition, 3M USA) Transfers were installed, changing the transfer screw (Figure 11). Once the impression was taken, implant for a short screw, in order to be able to perform the analogues were placed into the impression and the transference with the mouth closed. The flap was working model was obtained. closed using Ethicon non resorbable silk suture 4-0 (Johnson and Johnson, USA). The multifunctional surgical guide was used to achieve the transference impression and record

Figure 7. Surgical guide in place, pre-visualizing implant position.

Figure 5. Extraction of all teeth.

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Figure 8. Implants’ occlusal view, showing tilting of the two Figure 6. Opening of maxillary sinuses. most distally placed implants. Contreras MI et al. Atrophic maxilla rehabilitation 252

All laboratory steps were followed in the the office for occlusal adjustment and installation conventional manner. After 24 hours, a test of (Figures 12 to 15). the teeth in wax was undertaken to double-check The patient was treated with four dental implants, all phonetic and esthetic parameters. Once the placed according to the «All-on-Four» technique in infrastructure was completed, radiographic and the maxilla as well as a ﬁ xed prosthesis. The patient clinical settling were assessed. The structure was was subjected to a 12 month follow-up period, and then sent to the dental laboratory to be completed. to this date, is still satisfied with treatment results. One day after this test, the prosthesis returned to No perceptible clinical or radiographic changes were observed around the dental implants. To this date, there have been no complications either in the prosthesis or the implants. The patient is scheduled for a quarterly follow-up, mainly to determine effectiveness of home-administered oral care (Figures 16 to 18).

DISCUSSION

The tilted implant technique was introduced to treat atrophic maxillas. These maxillas generally have preserved the alveolar ridge in the region of the pre- maxilla between canines, which is distally limited by

Figure 9. Impression transfers linked to surgical guide.

Figure 10. Inter-occlusal record. Figure 12. Test of teeth in wax.

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Figure 11. Impression with closed mouth. Figure 13. Placement of completed prosthesis. Revista Odontológica Mexicana 2014;18 (4): 249-254 253

Figures 14 and 15.

Occlusal view of the prosthesis and patient’s smile. the anterior wall of the maxillary sinus at both sides. According to bio-engineering studies, distally Pneumatization of the maxillary sinus might require the placed implants must be rigidly linked to other following: placement of distally tilted, longer implants, implants, so that, upon binding, the geometrical installed areas of greater bone density, screws disposition of the outfit implant/prosthesis will be merging near the region of ﬁ rst molars, improving thus greater, achieving thus a more bio-mechanically the geometric disposition of the prosthesis/implant favorable system.9 A ten-year retrospective study ensemble. If the aforementioned technique were not to assessed the survival index of prostheses/implants be used, these regions would receive short implants or in 156 patients which had been rehabilitated with even grafts, and this would increase case complexity, prosthesis placed on four and six implants. Results as well as treatment time and cost.3-5 revealed the fact that, after ten years, survival index Opposite to what might be desirable, more distally for implants and prostheses was the same for both placed implants are responsible for the absorption and groups.10 Dr Maló, in 2003,11 in a retrospective, clinical dissipation of occlusal forces of greater might. They are study, assessed immediate-load protocols with four shorter due to the sinuses’ anatomy.6,7 With distally tilted implants (All-on-Four). In the study, it was concluded implants the length of the prosthesis supported polygon that use of four immediate-load implants with ﬁ xed increases and the cantilever extension decreases.5,8 prosthesis in the maxilla shows a high survival rate after one year, and that tilting of posterior implants was compatible with survival rate. Callandriello R et al., in 200512 published a prospective study where they assessed rehabilitations in atrophic maxillas with the use of tilted implants and early immediate load. A 96.7% survival rate was reported, and they reached the conclusion that use of this technique in edentulous jaws decreased general treatment time, especially surgery time and represented a lower cost. These factors benefit the patient as well as the clinical operator. Dr Ferreira et al.,13 in 2004 suggested the use Figure 16. One year post operative X-ray. of this technique in cases of atrophic maxillas, they www.medigraphic.org.mxwww.medigraphic.org.mx

Figures 17 and 18.

Clinical circumstances of the patient one year after prosthesis placement. Contreras MI et al. Atrophic maxilla rehabilitation 254

suggested that tilting of implants in a posterior-anterior occluding with complete dentures. International Journal of Oral direction allows bi-cortical anchorage in denser bone, Maxillofacial Implants. 1990; 5 (1): 277-283. 6. Aparicio C, Arevalo X, Ouzzani W, Granados C. A retrospective allowing thus placement of longer implants. This favors clinical and radiographic evaluation of tilted implants used in primary stability and use of functional immediate load the treatment severely resorbed edentulous maxillary. Appl protocol. Osseointegration Res. 2003; 1: 17-21. 7. Reiser GM. Implant use in the tuberosity, pterygoid, and palatine region: anatomic and surgical considerations. In: Nevisns M, CONCLUSION Melloning JT. Implant therapy. Quintessence Books. 1998; 2: 197-207. Based on reviewed studies, use of tilted implants is 8. Benzing UR, Gall H, Weber H. Biomechanical aspects of two different implant-prosthetic concepts for edentulous maxillary. recommended in cases of moderate maxillary atrophy. International Journal of Oral Maxillofacial Implants. 2004; 35 (6): EsteMain documento advantages es elaborado of this por technique Medigraphic when compared to 188-198. bone graft or zygomatic implant techniques are lesser 9. Skalak R, Zhao Y. Similarity of stress distribution in bone for surgical morbidity as well as optimal use of the residual various implant surface roughness heights of similar form. Clinical Implant Dentistry and Related Research. 2000; 2 (4): alveolar ridge. Placement of implants in a region of 225-230. denser bone tissue allows for lesser total treatment 10. Brånemark PI, Svensson B, Van Steenberghe D. Ten-year time, lesser cost and avoidance of multiple surgeries. survival rates of fixed prostheses on four or six implants ad modum Brånemark in full edentulismo. Clinical Oral Implant Research. 1995; 6 (4): 227-231. REFERENCES 11. Maló P, Rangert B, Nobre M. «All-on-Four» immediate- function concept with Brånemark system implants for 1. Brånemark PI. Osseointegration and its experimental completely edentulous mandibles: a retrospective clinical background. Journal of Prosthetic Dentistry. 1983; 50 (3): 399- study. Clinical Implant Dentistry Related Research. 2003; 410. (Supp 1): 2-9. 2. Bezerra F, Azoubel E. Alternativas cirúrgicas no tratamento 12. Callandriello R, Tomantis M. Simpliﬁ ed treatment of the atrophic da maxila atrófica. In: Bezerra F, Lenharo A. Terapia clínica posterior maxilla via immediante/early function and tilted avançada em implantodontia. São Paulo: Artes Médicas; 2002. implants: a prospective 1-year clinical study. Clinical Implant p. 159. Dentistry Related Research. 2005; (Supp1): 1-12. 3. De Leo C. Carga imediata em implantes osseointegrados 13. Ferreira AR, Bezerra JB, De Souza SW, Torres E, Da Rocha BV, inclinados: aumentando a superfície de ancoragem: relato de Lenharo A. O uso de implantes inclinados com carga imediata funcional na reabilitação da maxila completamente edêntula. dois casos. Odonto Ciencia. 2002; 17: 231-238. Innovations Journal. 2004; 6: 33-38. 4. Kahnberg KE, Nystrom E, Bartholdsson L. Combined use of bone grafts and Branemark ﬁ xtures in the treatment of severely resorbed maxillary. International Journal of Oral Maxillofacial Implants. 1989; 4 (4): 297-304. Mailing address: 5. Falk H, Laurell L, Lundgren D. Occlusal interferences and Iván Contreras Molina cantilever joint stress in implant-supported prostheses E-mail: [email protected]